Genome Property Definition Page

Accession

GenProp0317

Name

CRISPR system, I-B subtype, Tneap branch

Type

SYSTEM

Description

CRISPR repeats are by definition Clustered Regularly Interspaced Short Palindromic Repeats, described by Jansen [1]. Certain proteins, including Cas1 to Cas4, are found only in genomes with CRISPR repeats, and are near these repeats. Jansen, et al. describe CRISPR loci as having direct repeats, varying in size from 21 to 37 bp, interspaced by similarly sized non-repetitive sequences. Variants of CRISP/Cas loci (subtypes) have been described (Haft, Selengut, et al., submitted) in which certain groups of subtype-specific genes are found in addition to characteristic sets of the more widely distributed cas genes. The Tneap subtype, so named because this subtype is the only one found in the genome of Thermotoga neapolitana DSM4359, consists of cas1-5 and the subtype specific genes cst1-2. The repeats associated with this subtype tend to have a periodicity of 66 nucleotides. This subtype is found both in Archaea and Bacteria (with the notable exclusion of the Proteobacteria).